Modern warfare is based on mission speed, high lethality per round, and minimizing collateral damage. These criteria require projectiles capable of delivery munitions with high precision. Unguided artillery shells follow a ballistic trajectory, which is generally predictable but practically results in larger variability in the trajectory at ranges greater than 20 miles due to variations in atmospheric conditions; wind speed and direction, temperature, precipitation and the like. Variations in the weapons system; manufacturing tolerances, barrel condition, propellant charge temperature and gun laying errors may also contribute to variability in the shell trajectory. As the ballistic range increases, the potential impact of the projectile variation grows until the projectile delivered lethality is too low to effectively execute the fire mission.
Precision in such weapons comes at a high cost. Fully guided rounds are expensive and use GPS/IMU technology to precisely guide the missile to a target. Such high cost systems are not easily modified across the millions of artillery rounds in existing inventories or easily integrated into the design of new artillery rounds. Further, control surfaces including fins (e.g., canards), are sized, shaped and angled based upon the dimensions, mass moment of inertia and weight of the projectile. The control surfaces used with a projectile of one caliber (e.g., 155 mm) are less useful and actually degrade trajectory control of a projectile having a different caliber (e.g., 105 mm).